Module: REXML::Functions

Included in:
QuickPath, XPath
Defined in:
lib/rexml/functions.rb

Overview

If you add a method, keep in mind two things: (1) the first argument will always be a list of nodes from which to filter. In the case of context methods (such as position), the function should return an array with a value for each child in the array. (2) all method calls from XML will have “-” replaced with “_”. Therefore, in XML, “local-name()” is identical (and actually becomes) “local_name()”

Constant Summary collapse

@@context = 
nil
@@namespace_context = 
{}
@@variables = 
{}

Class Method Summary collapse

Class Method Details

.boolean(object = nil) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 278

def Functions::boolean( object=nil )
  if object.kind_of? String
    if object =~ /\d+/u
      return object.to_f != 0
    else
      return object.size > 0
    end
  elsif object.kind_of? Array
    object = object.find{|x| x and true}
  end
  return object ? true : false
end

.ceiling(number) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 374

def Functions::ceiling( number )
  number(number).ceil
end

.compare_language(lang1, lang2) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 325

def Functions::compare_language lang1, lang2
  lang2.downcase.index(lang1.downcase) == 0
end

.concat(*objects) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 153

def Functions::concat( *objects )
  objects.join
end

.contains(string, test) ⇒ Object

Fixed by Mike Stok



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# File 'lib/rexml/functions.rb', line 163

def Functions::contains( string, test )
  string(string).include?(string(test))
end

.context=(value) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 20

def Functions::context=(value); @@context = value; end

.count(node_set) ⇒ Object

Returns the size of the given list of nodes.



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# File 'lib/rexml/functions.rb', line 42

def Functions::count( node_set )
  node_set.size
end

.false ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 302

def Functions::false(  )
  false
end

.floor(number) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 370

def Functions::floor( number )
  number(number).floor
end

.get_namespace(node_set = nil) ⇒ Object

Helper method.



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# File 'lib/rexml/functions.rb', line 69

def Functions::get_namespace( node_set = nil )
  if node_set == nil
    yield @@context[:node] if defined? @@context[:node].namespace
  else
    if node_set.respond_to? :each
      node_set.each { |node| yield node if defined? node.namespace }
    elsif node_set.respond_to? :namespace
      yield node_set
    end
  end
end

.id(object) ⇒ Object

Since REXML is non-validating, this method is not implemented as it requires a DTD



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# File 'lib/rexml/functions.rb', line 48

def Functions::id( object )
end

.lang(language) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 307

def Functions::lang( language )
  lang = false
  node = @@context[:node]
  attr = nil
  until node.nil?
    if node.node_type == :element
      attr = node.attributes["xml:lang"]
      unless attr.nil?
        lang = compare_language(string(language), attr)
        break
      else
      end
    end
    node = node.parent
  end
  lang
end

.last ⇒ Object

Returns the last node of the given list of nodes.



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# File 'lib/rexml/functions.rb', line 33

def Functions::last( )
  @@context[:size]
end

.local_name(node_set = nil) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 52

def Functions::local_name( node_set=nil )
  get_namespace( node_set ) do |node|
    return node.local_name
  end
end

.method_missing(id) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 390

def Functions::method_missing( id )
  puts "METHOD MISSING #{id.id2name}"
  XPath.match( @@context[:node], id.id2name )
end

.name(node_set = nil) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 62

def Functions::name( node_set=nil )
  get_namespace( node_set ) do |node|
    node.expanded_name
  end
end

.namespace_context ⇒ Object 



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# File 'lib/rexml/functions.rb', line 17

def Functions::namespace_context ; @@namespace_context ; end

.namespace_context=(x) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 15

def Functions::namespace_context=(x) ; @@namespace_context=x ; end

.namespace_uri(node_set = nil) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 58

def Functions::namespace_uri( node_set=nil )
  get_namespace( node_set ) {|node| node.namespace}
end

.normalize_space(string = nil) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 225

def Functions::normalize_space( string=nil )
  string = string(@@context[:node]) if string.nil?
  if string.kind_of? Array
    string.collect{|x| string.to_s.strip.gsub(/\s+/um, ' ') if string}
  else
    string.to_s.strip.gsub(/\s+/um, ' ')
  end
end

.not(object) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 292

def Functions::not( object )
  not boolean( object )
end

.number(object = nil) ⇒ Object

a string that consists of optional whitespace followed by an optional minus sign followed by a Number followed by whitespace is converted to the IEEE 754 number that is nearest (according to the IEEE 754 round-to-nearest rule) to the mathematical value represented by the string; any other string is converted to NaN

boolean true is converted to 1; boolean false is converted to 0

a node-set is first converted to a string as if by a call to the string function and then converted in the same way as a string argument

an object of a type other than the four basic types is converted to a number in a way that is dependent on that type



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# File 'lib/rexml/functions.rb', line 342

def Functions::number( object=nil )
  object = @@context[:node] unless object
  case object
  when true
    Float(1)
  when false
    Float(0)
  when Array
    number(string( object ))
  when Numeric
    object.to_f
  else
    str = string( object )
    # If XPath ever gets scientific notation...
    #if str =~ /^\s*-?(\d*\.?\d+|\d+\.)([Ee]\d*)?\s*$/
    if str =~ /^\s*-?(\d*\.?\d+|\d+\.)\s*$/
      str.to_f
    else
      (0.0 / 0.0)
    end
  end
end

.position ⇒ Object 



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# File 'lib/rexml/functions.rb', line 37

def Functions::position( )
  @@context[:index]
end

.processing_instruction(node) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 386

def Functions::processing_instruction( node )
  node.node_type == :processing_instruction
end

.round(number) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 378

def Functions::round( number )
  begin
    number(number).round
  rescue FloatDomainError
    number(number)
  end
end

.starts_with(string, test) ⇒ Object

Fixed by Mike Stok



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# File 'lib/rexml/functions.rb', line 158

def Functions::starts_with( string, test )
  string(string).index(string(test)) == 0
end

.string(object = nil) ⇒ Object

A node-set is converted to a string by returning the string-value of the node in the node-set that is first in document order. If the node-set is empty, an empty string is returned.

A number is converted to a string as follows

NaN is converted to the string NaN

positive zero is converted to the string 0

negative zero is converted to the string 0

positive infinity is converted to the string Infinity

negative infinity is converted to the string -Infinity

if the number is an integer, the number is represented in decimal form as a Number with no decimal point and no leading zeros, preceded by a minus sign (-) if the number is negative

otherwise, the number is represented in decimal form as a Number including a decimal point with at least one digit before the decimal point and at least one digit after the decimal point, preceded by a minus sign (-) if the number is negative; there must be no leading zeros before the decimal point apart possibly from the one required digit immediately before the decimal point; beyond the one required digit after the decimal point there must be as many, but only as many, more digits as are needed to uniquely distinguish the number from all other IEEE 754 numeric values.

The boolean false value is converted to the string false. The boolean true value is converted to the string true.

An object of a type other than the four basic types is converted to a string in a way that is dependent on that type.



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# File 'lib/rexml/functions.rb', line 116

def Functions::string( object=nil )
  #object = @context unless object
  if object.instance_of? Array
    string( object[0] )
  elsif defined? object.node_type
    if object.node_type == :attribute
      object.value
    elsif object.node_type == :element || object.node_type == :document
      string_value(object)
    else
      object.to_s
    end
  elsif object.nil?
    return ""
  else
    object.to_s
  end
end

.string_length(string) ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 220

def Functions::string_length( string )
  string(string).length
end

.string_value(o) ⇒ Object

A node-set is converted to a string by returning the concatenation of the string-value of each of the children of the node in the node-set that is first in document order. If the node-set is empty, an empty string is returned.



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# File 'lib/rexml/functions.rb', line 140

def Functions::string_value( o )
  rv = ""
  o.children.each { |e|
    if e.node_type == :text
      rv << e.to_s
    elsif e.node_type == :element
      rv << string_value( e )
    end
  }
  rv
end

.substring(string, start, length = nil) ⇒ Object

Take equal portions of Mike Stok and Sean Russell; mix vigorously, and pour into a tall, chilled glass. Serves 10,000.



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# File 'lib/rexml/functions.rb', line 187

def Functions::substring( string, start, length=nil )
  ruby_string = string(string)
  ruby_length = if length.nil?
                  ruby_string.length.to_f
                else
                  number(length)
                end
  ruby_start = number(start)

  # Handle the special cases
  return '' if (
    ruby_length.nan? or
    ruby_start.nan? or
    ruby_start.infinite?
  )

  infinite_length = ruby_length.infinite? == 1
  ruby_length = ruby_string.length if infinite_length

  # Now, get the bounds.  The XPath bounds are 1..length; the ruby bounds
  # are 0..length.  Therefore, we have to offset the bounds by one.
  ruby_start = ruby_start.round - 1
  ruby_length = ruby_length.round

  if ruby_start < 0
   ruby_length += ruby_start unless infinite_length
   ruby_start = 0
  end
  return '' if ruby_length <= 0
  ruby_string[ruby_start,ruby_length]
end

.substring_after(string, test) ⇒ Object

Kouhei fixed this too



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# File 'lib/rexml/functions.rb', line 179

def Functions::substring_after( string, test )
  ruby_string = string(string)
  return $1 if ruby_string =~ /#{test}(.*)/
  ""
end

.substring_before(string, test) ⇒ Object

Kouhei fixed this



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# File 'lib/rexml/functions.rb', line 168

def Functions::substring_before( string, test )
  ruby_string = string(string)
  ruby_index = ruby_string.index(string(test))
  if ruby_index.nil?
    ""
  else
    ruby_string[ 0...ruby_index ]
  end
end

.sum(nodes) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 365

def Functions::sum( nodes )
  nodes = [nodes] unless nodes.kind_of? Array
  nodes.inject(0) { |r,n| r + number(string(n)) }
end

.text ⇒ Object 



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# File 'lib/rexml/functions.rb', line 22

def Functions::text( )
  if @@context[:node].node_type == :element
    return @@context[:node].find_all{|n| n.node_type == :text}.collect{|n| n.value}
  elsif @@context[:node].node_type == :text
    return @@context[:node].value
  else
    return false
  end
end

.translate(string, tr1, tr2) ⇒ Object

This is entirely Mike Stok’s beast



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# File 'lib/rexml/functions.rb', line 235

def Functions::translate( string, tr1, tr2 )
  from = string(tr1)
  to = string(tr2)

  # the map is our translation table.
  #
  # if a character occurs more than once in the
  # from string then we ignore the second &
  # subsequent mappings
  #
  # if a character maps to nil then we delete it
  # in the output.  This happens if the from
  # string is longer than the to string
  #
  # there's nothing about - or ^ being special in
  # http://www.w3.org/TR/xpath#function-translate
  # so we don't build ranges or negated classes

  map = Hash.new
  0.upto(from.length - 1) { |pos|
    from_char = from[pos]
    unless map.has_key? from_char
      map[from_char] =
      if pos < to.length
        to[pos]
      else
        nil
      end
    end
  }

  if ''.respond_to? :chars
    string(string).chars.collect { |c|
      if map.has_key? c then map[c] else c end
    }.compact.join
  else
    string(string).unpack('U*').collect { |c|
      if map.has_key? c then map[c] else c end
    }.compact.pack('U*')
  end
end

.true ⇒ Object

UNTESTED



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# File 'lib/rexml/functions.rb', line 297

def Functions::true( )
  true
end

.variables ⇒ Object 



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# File 'lib/rexml/functions.rb', line 18

def Functions::variables ; @@variables ; end

.variables=(x) ⇒ Object 



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# File 'lib/rexml/functions.rb', line 16

def Functions::variables=(x) ; @@variables=x ; end